Add support for extra/custom annotations in secret-validation-hook

[akorp]

Add support for extra/custom annotations for secret-validation-hook (pod splunk-otel-collector-validate-secret) to control sidecar containers.

In our kubernetes cluster linkerd injects sidecar containers to all pods, except those with annotation linkerd.io/inject: disabled.
Since we don't have an option to add annotation for secret-validation-hook, pod splunk-otel-collector-validate-secret is getting into NotReady state - container validate-secret is successfully completed with exit code 0, but linkerd sidecar container linkerd-proxy keeps running. This blocks the helm release.